This is going to teach you about vectors : ) The speed of
the river and the direction makes it a vector and so you
must put in the right amount of speed for your boat and set
the right angle to get it across the river. 

The boat only has ten seconds so it must be fast to cross.
The distance across the river is 20m and you have 30 meters
before the end of the waterfall.

If you don't get it the first time refresh and try again.



Good luck.